Between Newton and Milford, the 29 mile Kittatinny Ridge section of the Appalachian Trail runs the northwest corner of the state on a 1,600 feet ridge with rocky outcrops high above the Delaware River. It begins at High Point State Park. Hike south along the ridge, staying the first night at Gren Anderson Shelter, 11.3 miles in, and camping in the oak forest on Rattlesnake Mountain, around mile 21, on the second. Finish hiking up with a 8.6-miler along the exposed quartzite escarpment to Millbrook-Blairstown Road.
To reach the hiking trailhead from Sussex, take SR 23 seven miles to the Appalachian Trail parking area at the crest of Kittatinny Ridge in High Point State Park. Leave a car 25 miles away at the AT parking area on Millbrook-Blairstown Road.
Overall, Appalachian Trail - Kittatinny Ridge is the 2nd most popular hiking trail of all 29 hikes in New Jersey.